gas exchange in humans

Question 1

name parts of the respiratory system

Answer 1

trachea
bronchus
bronchioles
alveoli
lung
rib
intercoastal muscles
diaphragm

Question 2

features of trachea

Answer 2

ciliated epithelium
goblet cells
rings of cartilage

Question 3

what does the bronchus contain

Answer 3

cilia and mucus

Question 4

lung features

Answer 4

enclosed in a pleural membrane
pleural fluid lubricates lungs

Question 5

features of alveoli

Answer 5

collagen and elastic fibres between them
lined with squamous epithilia
phagocytes inside

Question 6

features of goblet cell

Answer 6

cilia
secretory vesicles containing mucin
lots of mitochondria and ribosomes

Question 7

function of mucus

Answer 7

traps dust and bacteria

Question 8

function of cilia

Answer 8

beat regularly to move micro organisms and dust particles along with mucus

Question 9

function of cartilaginous rings

Answer 9

give the trachea support and rigidity

Question 10

function of epiglottis

Answer 10

closes over windpipe while eating to prevent food entering the airway

Question 11

function of squamous (flattened) epithelium

Answer 11

means diffusion pathway is shortened

Question 12

adaptations of alveoli

Answer 12

large surface area
diffusion gradient maintained from constant ventilation
1 cell thick
red blood cells slowed as they pass next to alveoli
red blood cells flattened against capillary walls

Question 13

order of structures O2 passes through into the capillary

Answer 13

alveolus
alveolar epithelial wall
gas exchange membrane
capillary endothelium
capillary
red blood cell

Question 14

what is surfactant

Answer 14

a phospholipid that coats the surfaces of the lungs

Question 15

function of surfactant

Answer 15

prevents alveoli from sticking together and collapsing

Question 16

order of occurrence during inspiration

Answer 16

diaphragm contacts and flattens
external intercostal muscles contract, pulling the ribs up and out
thorax volume increases
pressure in lungs decreases
air is pushed in to equalise the pressure

Question 17

order of occurrence during expiration

Answer 17

diaphragm relaxes and forms dome shape
external intercostal muscles relax pulling ribs down and in
thorax volume decreases
lung pressure increases
air is pushed out to equalise pressure

Question 18

what is meant by recoil

Answer 18

elastic tissue can stretch
recoils to an unstretched position
engages then collapses the lungs

Question 19

pulmonary ventilation rate equation

Answer 19

PV = tidal volume (dm3) x breathing rate

Question 20

purpose of spirometry

Answer 20

used to measure lung function (capacity of human lungs)
can be used to diagnose lung diseases

Question 21

define tidal volume

Answer 21

the volume of air breathed in and out without conscious effort

Question 22

define ventilation rate

Answer 22

number of breaths per minute

Question 23

define inspiratory reserve volume

Answer 23

the additional volume of air that can be inhaled with maximum effort after a normal inspiration

Question 24

expiratory reserve definition

Answer 24

the additional volume of air that can be forcibly exhaled after a normal exhalation

Question 25

vital capacity definition

Answer 25

the total volume of air that can be exhaled after a max inhalation

Question 26

residual volume definition

Answer 26

the volume of air remaining in the lungs after max exhalation (lungs can never be fully emptied)

Question 27

total lung capacity =

Answer 27

vital capacity + residual volume